2008-08-09

Electric Bike project part 1

Brian and I decided to build him an electric bike conversion so he can ride his bike to work. The problem with the ride normally is a gigantic hill on the way home. Our goal was to boost him up the hills, while still allowing him to bike normally (except with a heavy bike).

We based the design off of Eric Peltzer's Electric Bicycle. We modified the design to take into account a few major differences. We didn't want to weld anything, we wanted it to be cheaper, and we have access to a waterjet cutter.

Brian purchased a XYD-13 motor kit, which is a 600W motor that normally goes on a Currie Electric scooter. It came with a speed controller, and we had an option for a twist grip, or a thumb control. We also ordered a shaft, bearings, etc from McMaster Carr, and a small set of 10Ah batteries and charger. If he doesn't get enough range on the bike, the plan is to upgrade the batteries.

The motor came with an excellent one-way clutch built into the sprocket. We decided to keep this, which allows the motor pulley to freewheel while the bike is being pedaled.

Last weekend, after we had waterjet out the motor assembly frame, we spent a few hours assembling:
Full Gallery Link
The motor assembly


Preparing the output scprocket


Mounting the output sprocket


The fruits of the days efforts


Remaining items:
  • modify and mount the smaller pulley
  • get shorter bolts for the output sprocket
  • find and mount the bike rack to hold everything up
  • install the batteries, controller, and thumb control